The present invention relates to an exterior rearview mirror for mounting on a vehicle and, more particularly, to an extendable exterior rearview mirror for mounting on a vehicle which can be extended when the vehicle is being used for towing, for example towing a trailer, camper, or the like.
Until recently, towing mirrors included a fixed support or frame, which was rigidly mounted to the vehicle body, and a reflective element supported on and spaced from the vehicle body by the support or frame to provide rearview viewing of the towed object. For example, U.S. Pat. No. 3,119,591 to A. J. Malecki illustrates a typical rigidly mounted towing mirror assembly. However, these fixed extended rearview mirror assemblies increase the width of the vehicle often hampering normal maneuvering through passages including garage door openings, drive-through services, and the like. Furthermore, they are more vulnerable to being damaged or causing damage than conventional exterior rearview mirrors especially when used by an inexperienced driver. In some cases, the width of the vehicles was increased beyond the maximum width allowed by conventional vehicle transport trucks which deliver the vehicles to the dealership. Therefore, these mirror assemblies often required installation at the dealership which ultimately increased the cost of the vehicle.
More recently, several extendable exterior rearview mirrors have been developed. For example, in U.S. Pat. No. 5,513,048 to Chen and U.S. Pat. No. 5,489,080 to Allen, extendable rearview mirrors are disclosed which include telescoping members. The position of the mirror subassembly, which includes a reflective element and reflective element housing, is fixed in position by threaded fasteners, which require tools for adjustment. However, these assemblies tend to increase the vibration of the mirror assembly especially when the mirror subassembly is in the outboard position.
Consequently, there is a need for an extendable rearview mirror assembly that can provide for an extended field of view when towing and yet can be retracted to a normal operating position where it does not hamper maneuverability of the vehicle. In addition, the extendable rearview mirror assembly should have minimal impact on the vibration characteristics of the mirror assembly and be relatively easy to adjust between non-towing and towing positions without the need for tools.